What a non-domestic energy assessor examines, why floor plans and services information matter, and how to prepare a complex building. This guide is written for practical decision-making and links to the sources used for verification.
The building is divided into energy zones
A commercial EPC model reflects geometry, construction, activity areas and fixed services. The assessor may divide premises into zones according to use, heating, cooling, lighting and ventilation. Accurate floor plans can therefore save time and reduce uncertainty.
The assessment is not an operational energy audit. It models the building under standard assumptions so different premises can be compared.
Services and evidence can change the result
Heating and cooling plant, controls, hot water, lighting, mechanical ventilation and on-site generation all influence the calculation. Plant schedules, commissioning information, lighting layouts and product data can help the assessor identify systems accurately.
Where data cannot be verified, conservative defaults may be required. Arrange access to plant rooms, roof areas, meters and representative spaces, subject to site safety and permissions.
- Current floor plans and areas
- Building age and construction records
- HVAC plant and control information
- Lighting type and control details
- Renewable and metering information
- Access, security and site-safety arrangements
Agree scope before attendance
Confirm whether the instruction covers the whole building, a single unit or several separately occupied parts. Tell the assessor about vacant areas, shared services, shell-and-core space and recent alterations.
For complex premises, a pre-assessment information request is a sign of a careful process. A quote based only on a postcode may not reflect the work required.
Research and verification
Authoritative sources
Use these primary and specialist sources to check the current rule and read further.
Requirements can change and unusual properties may need specialist advice. Check the latest official source and the facts of the property before relying on a compliance conclusion.
